An RAF Bomber Command crew prepares to take off on a mission to Berlin in 1944. Photograph: Popperfoto/Popperfoto/Getty Images

After almost 70 years, the 55,573 dead of RAF Bomber Command are to be honoured in a prominent memorial at the western end of London's Piccadilly. This is no straightforward act of remembrance. Fighter Command has been acknowledged in a variety of ways, stretching back to the window and chapel in Westminster Abbey installed more than 60 years ago. Bomber Command veterans were given no campaign medal, despite the scale of losses, and Air Chief Marshal Harris was passed over when others got their peerage.

The problem with remembering Bomber Command has always been the profound ambivalence felt in British postwar society about the ethics of wartime bombing. Opinion polls made during the blitz found respondents divided evenly on the question of bombing enemy civilians – 46% for, 46% against. After the publicity given to the bombing of Dresden, and the less well-known, but more deadly, bombing of Hamburg, postwar opinion found it hard to reconcile Britain's image of a just war on behalf of shared liberal values with the killing of half a million enemy civilians.

During the war these doubts were covered over by repeated assurances in parliament and from RAF spokesmen that only military targets were ever attacked, broadly stretched though the concept was. Once it was clear that this had not been the case, and indeed that the central residential areas of cities were the intended target, it became more difficult for the bombing to be absorbed into the popular memory of the war, while, with Fighter Command's role in the Battle of Britain and the blitzed British, there was no problem at all. Seventy years later, the gulf still exists between those who see British bombing as an unfortunate lapse from an otherwise morally secure war effort, and those who think that bombing was entirely ethically justified as a response to the blitz and the need to end the war by any means against an evil and dangerous enemy.

The argument is not, of course, as simple as that. The aircrew who are to be honoured with the new memorial did not volunteer to bomb city centres and kill civilians indiscriminately. At every briefing they were told about the industrial and military targets that lay within the area they were told to bomb. No doubt many, perhaps most, knew that their bombs would not just hit the designated objectives, but also shatter the city that housed them.

Yet recollections by surviving crew make it clear that, in this, one of the harshest environments of the war, exposed to continuous danger not once, but 30 times if they survived (and most did not), their moral reference points were their immediate comrades on board and the other flyers around them, not whatever might be happening, invisibly, on the ground.

There is a real sense in which the crew of Bomber Command were victims too, sent out often in poor weather, against distant targets, cold, fearful and aware of the hungry presence of death, by commanders who knew that survival rates were poor and that the military-industrial targets were a mere front for a deliberate policy of killing civilians and destroying the civilian milieu, a policy first developed during the course of 1941. This was a policy shielded from the public and from the crews, because it raised awkward questions. Among those in the know, it was felt that the greater moral failing would be to abstain from using every means to end the war and preserve British lives.

No one needs to be Socrates to work out that two wrongs do not make a right. If German bombing of civilians was wrong, so too was British. Those who made policy understood this. Yet it was possible for the RAF chief of staff, Charles Portal, to suggest to Churchill, Roosevelt and the assembled combined chiefs at Quebec in August 1943 that the RAF hoped to kill 900,000 German civilians without raising any demur among western leaders except over its feasibility. If Eisenhower had made this one of his operational pledges when the allied armies arrived in Germany, he would have been pilloried. Somehow bombing created a moral blind spot that allowed airmen to do to the enemy population what soldiers could not.

The opening of the Bomber Command monument is perhaps a moment to try to find some common ground over this unresolved element of Britain's wartime legacy. There is a good case for recognising the sacrifice of the 55,000-plus who died, just as we remember the wasted dead at the Somme or Passchendaele. But it is surely time that the ethical subterfuge performed all through the war, in pretending that city areas were militarily justifiable targets, was confronted honestly.

The result is a paradox. While allowing the dead of Bomber Command at last to share in the common status of wartime victims, the responsibility of those who shaped and approved of British bombing strategy and urged it on to ever higher levels of destruction cannot be sidestepped. The military will do whatever they are ordered or permitted to do according to the strategic directives they have been given; it is those who give the permission who need to be held to account.